Restrict Access to All Key Files

中级别 1自动化bind

说明

The TSIG keys should be readable only by the named and root accounts. No other user accounts or groups should have read access. Note that BIND often creates a session key on startup for usage by nsupdate -l. Both the $BIND_HOME and $RUNDIR are included since the session key should also have the recommended permissions. The audit finds files containing "secret" under $BIND_HOME and $RUNDIR and requires owner root/named, group root/named (bind on Debian) and no group/other write. $BIND_HOME is taken as the existing ones of /var/named (RHEL, including a chroot), /etc/bind and /var/cache/bind (Debian/Ubuntu) and $RUNDIR as /run/named; the runtime directories (dynamic, slaves, data, run, log, tmp, /var/cache/bind) are excluded where the benchmark excludes them.

检查方式

审计方法: Shell 命令

shell

BH=''; for d in /var/named /etc/bind /var/cache/bind; do [ -d "$d" ] && BH="$BH $d"; done
[ -n "$BH" ] || { echo 'no BIND directory found'; exit 1; }
RUN=''; for d in /run/named /var/run/named; do [ -d "$d" ] && { RUN=$d; break; }; done
G='-group root'; U='-user root'; for a in named bind; do grep -q "^$a:" /etc/group 2>/dev/null && G="$G -o -group $a"; grep -q "^$a:" /etc/passwd 2>/dev/null && U="$U -o -user $a"; done
RT='^(/var/named(/chroot/var/named)?/(dynamic|slaves|data)|/var/named/chroot/(var/)?run/named|/var/named/chroot/var/log|/var/named/chroot/(var/)?tmp|/var/cache/bind|/run/named|/var/run/named)(/|$)'
files=$(find $BH $RUN -type f 2>/dev/null | xargs -r grep -l secret 2>/dev/null | sort -u)
[ -n "$files" ] || { echo compliant; exit 0; }
bad=$(for f in $files; do find "$f" \( \! \( $U \) -o \! \( $G \) -o -perm /022 \) -print; done)
[ -z "$bad" ] && echo compliant || { echo 'key files with wrong owner/group or group/other write:'; printf '%s\n' "$bad"; }

预期输出: compliant

修复方式

修复方法: 操作指南或基础设施补丁

Perform the following for remediation: ; Use the command below to find secret key files. Review the list of key files, and delete any unused or unnecessary key files. Recreate the file list, after deleting any unused files. # find $BIND_HOME $RUNDIR -type f | xargs fgrep -l secret | sort -u > $TMPDIR/key_files.txt ; Change the ownership, group and permissions on the key files. # xargs -a $TMPDIR/key_files.txt chown -R root # xargs -a $TMPDIR/key_files.txt chgrp -R named # xargs -a $TMPDIR/key_files.txt chmod o-r ; Remove the temporary file, rm $TMPDIR/key_files.txt

属性

操作系统: 任意
标签: binddnstsig
参考: CIS ISC BIND DNS Server 9.11 Benchmark v1.0.0 - 4.4 Restrict Access to All Key Files

检查本机

请在您有权审计的机器上运行此命令。扫描为只读操作。

shell

tmaegis scan --target bind